Oscillating saws typically include a measuring wheel which is made to roll on a surface of sawed lumber whereby the length of the sawed lumber can be determined by the rotational displacement of the measuring wheel. Typically, the sawed lumber is guided along the conveyed path to the measuring wheel by a pneumatic hold-down or centering roller located upstream from the measuring wheel. A portion of the measuring wheel is elastically pressed into the conveyer path. When the lumber engages the measuring wheel, the measuring wheel is forced out of the conveyer path and onto the surface of the sawed lumber to be measured. The measuring accuracy of the system is dependent on the instantaneous rotation of the measuring wheel upon contact with the sawed lumber. However, at conveying speeds of 4 mm/msec, such devices are inherently inaccurate due to the slippage of the measuring wheel when it initially engages the sawed lumber.
Accordingly, it is therefore desirable to accelerate the measuring wheel prior to engagement with the sawed lumber to reduce slippage and increase the accuracy of the measurement.